The present invention relates to a magnetic liquid seal which seals a gap defined between two members by means of a magnetic liquid.
Magnetic liquid seals are generally employed to seal rotating shafts. A typical conventional magnetic liquid seal has as shown in the specification of U.S. Pat. No. 4,357,021, a permanent magnet and two pieces of magnetic pole which are respectively provided on both sides thereof for applying a magnetic entrapped force to a magnetic liquid in the gap defined at a rotating shaft. The permanent magnet and the two pieces of magnetic pole are made of a metal.
The above-described prior art, which has a metallic permanent magnet and metallic pieces of magnetic pole, has the problem that, when these members are mounted on a non-magnetic member, it is necessary to process the metallic members so that they have a relatively high degree of machining accuracy, which means that it has heretofore been difficult to assemble them together at high efficiency.